/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package groovy.xml.markupsupport;

import java.util.Optional;

public class AllControlToUndefined extends StandardControlToUndefined {
    @Override
    public Optional<String> apply(Character ch) {
        if (Character.isISOControl(ch) || isNonCharacter(ch)) {
            return Optional.of("\uFFFD");
        }
        return super.apply(ch);
    }

    private boolean isNonCharacter(char ch) {
        return 0xFDD0 <= ch && ch <= 0xFDEF || ((ch ^ 0xFFFE) == 0 || (ch ^ 0xFFFF) == 0);
    }
}
